https://repository.kopri.re.kr/handle/201206/15759 2026-04-05T21:39:17Z https://repository.kopri.re.kr/handle/201206/16463 Title: Monitoring Subglacial Lake Activity in the David Glacier Region, East Antarctica, Using a DInSAR Displacement Integration Approach Authors: Kim Taewook; Han Hyangsun; Lee Hoonyol; Ju, Hyeon Tae Abstract: Subglacial lakes significantly influence ice sheet dynamics, necessitating precise monitoring of their activity. This study presents a novel approach that integrates differential interferometric synthetic aperture radar (DInSAR) displacements from Sentinel-1 data to estimate high-resolution time series of ice sheet surface elevation changes associated with subglacial lake activity. Applying this approach to the David Glacier region in East Antarctica from 2016 to 2023, we identified and analyzed the activity of Lake David(2) and newly identified subglacial lakes, David(2-1) and David(A). The ice sheet elevation changes derived from the DInSAR displacement integration showed strong agreement with Ice, Cloud, and land Elevation Satellite-2 observations and allowed for detailed monitoring of subglacial lake activity. The ice sheet surface above Lake David(A) showed a marked rise in early 2016 due to lake filling, followed by a stable period until 2020. A rapid surface decline occurred in late 2020 due to drainage. Since 2021, the surface decline has continued at slower rates, indicating gradual water level lowering. Lake David(2-1) filled by early 2021 and subsequently exhibited alternating drainage and filling. The ice sheet surface above Lake David(2) exhibited sustained uplift until 2020, attributed to continuous water filling, and then transitioned to a phase of drainage. Hydraulic potential-derived basal water pathways suggested that Lake David(A) was likely supplied by undetected inflows, while Lake David(2) primarily received water from a southern pathway rather than from Lake David(2-1). This study demonstrates the effectiveness of time-series DInSAR for subglacial lake monitoring, overcoming limitations of altimetry-only observations and providing insights into subglacial hydrology and ice sheet dynamics. 2025-08-01T00:00:00Z https://repository.kopri.re.kr/handle/201206/16360 Title: Airborne and Spaceborne Mapping and Analysis of the Subglacial Lake D2 in David Glacier, Terra Nova Bay, Antarctica Authors: Ju, Hyeon Tae; Kang, Seung-Goo; Han Hyangsun; Beem Lucas H.; Ng Gregory; Chan Kristian; Kim Taewook; Lee, Joohan; Lee, Jong Ik; Kim Yeadong; Pyun Sukjoon Abstract: During the 2018-2019 Antarctic summer, the Korea Polar Research Institute and the University of Texas Institute for Geophysics collaborated on a helicopter-based ice-penetrating radar (IPR) survey over the active subglacial lake D2 (SLD2), located in the midstream of the David Glacier, Terra Nova Bay, Antarctica. This study investigates the relationship between SLD2 water levels and fluctuations in glacial surface elevation (up to 3.6 m) and delineates subglacial lakes within the study area. We provide a comprehensive analysis based on integrated data from IPR (2018), Sentinel-1 double-differential interferogram synthetic aperture radar (DDInSAR) (2017-2022), ICESat-2 laser altimeter (2019-2022), and KOMPSAT-5 synthetic aperture radar (2021 and 2023). The concave bedrock structure and low hydraulic head areas concentrate subglacial meltwater, facilitating water accumulation and retention, forming a lake. The SLD2 lake complex is identified based on bed topography, hydraulic gradient, and relative bed reflection intensity. Its area is approximately 1/9.2 of the lake area estimated through remote sensing. Our analysis suggests that variations in water supply and discharge along the subglacial channel network influence lake water levels, as evidenced by a surface elevation increase of up to 3.69 m in the SLD2 area from 2019 to 2022. Additionally, the presence of crevasses and incoherence in the DDInSAR imagery suggests that these subglacial lakes impact glacier flow velocity. 2025-01-01T00:00:00Z